RT Journal Article SR Electronic T1 Long-term outcomes in distinct phenogroups of patients with primary mitral regurgitation undergoing valve surgery JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 305 OP 313 DO 10.1136/heartjnl-2022-321305 VO 109 IS 4 A1 Kwak, Soongu A1 Lee, Seung-Ah A1 Lim, Jaehyun A1 Yang, Seokhun A1 Choi, Hong-Mi A1 Hwang, In-Chang A1 Lee, Sahmin A1 Yoon, Yeonyee Elizabeth A1 Park, Jun-Bean A1 Kim, Hyung-Kwan A1 Kim, Yong-Jin A1 Song, Jong-Min A1 Cho, Goo-Yeong A1 Kim, Kyung-Hwan A1 Kang, Duk-Hyun A1 Kim, Dae-Hee A1 Lee, Seung-Pyo YR 2023 UL http://heart.bmj.com/content/109/4/305.abstract AB Objectives Patients with mitral regurgitation (MR) may be heterogeneous with different risk profiles. We aimed to identify distinct phenogroups of patients with severe primary MR and investigate their long-term prognosis after mitral valve (MV) surgery.Methods The retrospective cohort of patients with severe primary MR undergoing MV surgery (derivation, n=1629; validation, n=692) was analysed. Latent class analysis was used to classify patients into subgroups using 15 variables. The primary outcome was all-cause mortality after MV surgery.Results During follow-up (median 6.0 years), 149 patients (9.1%) died in the derivation cohort. In the univariable Cox analysis, age, female, atrial fibrillation, left ventricular (LV) end-systolic dimension/volumes, LV ejection fraction, left atrial dimension and tricuspid regurgitation peak velocity were significant predictors of mortality following MV surgery. Five distinct phenogroups were identified, three younger groups (group 1–3) and two older groups (group 4–5): group 1, least comorbidities; group 2, men with LV enlargement; group 3, predominantly women with rheumatic MR; group 4, low-risk older patients; and group 5, high-risk older patients. Cumulative survival was the lowest in group 5, followed by groups 3 and 4 (5-year survival for groups 1–5: 98.5%, 96.0%, 91.7%, 95.6% and 83.4%; p<0.001). Phenogroups had similar predictive performance compared with the Mitral Regurgitation International Database score in patients with degenerative MR (3-year C-index, 0.763 vs 0.750, p=0.602). These findings were reproduced in the validation cohort.Conclusion Five phenogroups of patients with severe primary MR with different risk profiles and outcomes were identified. This phenogrouping strategy may improve risk stratification when optimising the timing and type of interventions for severe MR.The data of this study may not be available because of ongoing projects using this data.